What is Onion Extract?
Onion Extract (Allium cepa L.) is a natural botanical ingredient derived from bulb tissues of the onion plant, widely recognized for its anti-fibrotic, anti-inflammatory, antioxidant, and wound-healing properties.Rich in flavonoids (quercetin, kaempferol), phenolic acids, sulfur compounds (cysteine and allicin derivatives), and vitamin C, onion extract is extensively used in dermatological and cosmetic products aimed at reducing scars, improving skin texture, and enhancing wound recovery.
Effects on Skin and Barrier Properties
Onion extract promotes skin healing and scar reduction through multiple synergistic mechanisms:
- Wound Healing & Anti-Fibrotic: Regulates fibroblast activity and enhances MMP-1 expression, promoting balanced ECM remodeling, faster re-epithelialization, and reduced hypertrophic or keloid scarring.
- Anti-Inflammatory: Suppresses IL-6, TNF-α, and NF-κB pathways, minimizing redness, swelling, and irritation while supporting microbial balance and protection against infection.
- Antioxidant & Photoprotective: Rich in quercetin and kaempferol, which neutralize free radicals, protect against UV-induced damage, and preserve ECM integrity.
- Brightening & Tone Refining: Inhibits tyrosinase activity and supports continuous ECM renewal, improving post-inflammatory hyperpigmentation and overall skin smoothness.
Research Insights
- MMP-1 Modulation and Anti-Fibrotic Mechanism: Onion extract and quercetin stimulate MMP-1 expression in fibroblasts and in vivo, promoting ECM remodeling and reducing fibrotic tissue formation. Enhanced MMP-1 activity improves scar elasticity and decreases scar thickness.
- Cellular Signaling and Healing Promotion: Quercetin activates ERK and JNK MAPK signaling, supporting cell proliferation, differentiation, and migration essential for tissue repair. These effects accelerate wound closure without inducing excessive inflammation.
- Clinical Studies and Topical Application: Topical onion extract gels significantly improve scar appearance, texture, and redness after 4–8 weeks of regular use. Clinical evaluations confirm excellent skin tolerance and suitability for sensitive or post-procedure applications.
Applications
- Medical use: Post-surgical scar gels, burn and wound healing creams.
- Cosmetic use: Anti-scar serums, soothing creams, repairing masks, and brightening treatments.
- Functional claims: Anti-fibrotic, wound healing promoter, anti-inflammatory, antioxidant, and skin tone refiner.
Conclusion
Onion extract is a multifunctional botanical active that supports the skin’s natural repair process by balancing extracellular matrix ECM synthesis and degradation. Through MMP-1 modulation, antioxidant protection, and fibroblast regulation, it effectively reduces scar formation, enhances healing, and improves overall skin texture. Its dual antioxidant and remodeling actions make it a versatile ingredient for modern wound care and cosmetic formulations targeting skin recovery and regeneration.
References
Onion extract and quercetin induce matrix metalloproteinase-1 in vitro and in vivo (Cho et al.) — shows that onion extract upregulates MMP-1 in human fibroblasts and in animal models: https://pubmed.ncbi.nlm.nih.gov/20127038/
Gels and patches containing onion extract and allantoin as safe and effective in scars — patch containing onion extract plus allantoin in C-section scars:https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2020.569514/full
